Canine biscuit containing discrete meat and/or meat by-product particles and method for making same

ABSTRACT

A dry hard canine biscuit having visually apparent, discrete meat and/or meat by-product particles distributed substantially uniformly through the biscuit is obtained by blending the non-fat solids portion of a canine biscuit dough with the particles which are substantially inert with respect to the dog biscuit dough, mixing the dry-blended mixture with water and with the fat portion of the pet biscuit dough to form a dough, forming the dough into pieces using low-shear, non-cooking forming conditions, and baking and drying the formed pieces to obtain a microbiologically stable product which can be packaged without a barrier material. Meat and/or meat by-product particle inertness is made possible by using particles having (1) a moisture content of 35 percent by weight or less and (2) a water activity which is less than the water activity of said biscuit dough. The substantial absence of meat particle color bleed into the biscuit is principally due to the use of meat products wherein the color is formed as part of the protein matrix. The discrete, visually apparent dehydrated meat particles enhance the palatability and visual attractiveness of the dry biscuit.

This is a continuation of application Ser. No. 614,601, filed on May 29,1984, now U.S. Pat. No. 4,551,343, which is a continuation-in-part ofSer. No. 549,352, filed on Nov. 7, 1983, now U.S. Pat. No. 4,546,001,which is a continuation-in-part of application Ser. No. 341,969, filedon Jan. 22, 1982, now U.S. Pat. No. 4,454,163.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for incorporating animal protein intoa biscuit dough to obtaina dry, hard canine biscuit. The invention alsorelates to a dry, hard canine biscuit.

2. Description of the Prior Art

Dry pet foods are commonly cereal type materials having a low moisturecontent of less than about 15 percent by weight. As a result of theirlow moisture content, they resist mold growth and bacterial spoilage.Additionally, they can often be packaged and stored in containers, suchas a box, without the need for hermetic sealing and without the need fora moisture barrier. Dry pet foods typically have low palatabilitybecause of their low moisture content.

The incorporation of meat products, fish products and poultry productsinto a farinaceous pet food to improve palatability and to improvenutritional values of dry pet foods, intermediate moisture products andhigh moisture content pet foods (more than about 50 percent by weightwater) is known in the art.

U.S. Pat. No. 3,946,123 discloses an aqueous suspension or broth of meatand meat by-products consisting in part or entirely of fish and flavoredcereal chunks. The meat and meat by-products that may be used includethose of fowl and fish as well as that of mammal such as cattle, swine,goats and the like. Due to the high moisture content of the product, itmust be packaged in cans. In U.S. Pat. No. 4,158,706 a high moisture petfood product containing farinaceous and proteinaceous components such asmeats, fish and poultry is impregnated with a preservative such assuccinic acid to enable packaging within a paper or polymer film. Thesehigh moisture content of products have a high shipping weight for agiven amount of nutritive value and do not provide a hard surface forthe strengthening of gums and for the removal of plaque from teeth.

The production dry pet foods which contain proteinaceous and farinaceousmaterial is disclosed in U.S. Pat. Nos. 3,962,462, 4,020,187, 4,039,689,4,055,681, 4,145,447, 4,215,149 and 4,229,485.

In U.S. Pat. No. 3,962,462 the ingredients are first dry-blended andthen water and water-containing ingredients are added until a cohesivedough is formed. A stabilizing system comprising a sugar, an edible acidand an antimycotic provides stability within the pet food when the petfood is subjected to semi-moist conditions. The product is produced inwafer form for packaging with a semi-moist pet food. The proteinaceousmaterial includes meat, such as the flesh of cattle, swine, sheep,poultry and fish as well as various meals such as meat and bone meal,fish meal and the like.

In U.S. Pat. No. 4,020,187 tallow or lard is added to a water slurry ofa ground mixture of meat and meat by-products to raise the resulting fatcontent of the mixture to at least 25 percent. The resultant mixture isthen homogenized to liquefy and reduce the particle size to uniformlydistribute the fat content through the meat mixture. Dry farinaceousingredients are ground and added to the homogenized meat mixture. Theblended mixture is subjected to a temperature of from 225° to 325° F. ata pressure of at least about 50 p.s.i. The product is expanded, cut anddried to obtain a product having a final moisture content of from 7 to15 percent. The product, it is disclosed, is not externally greasy andmay be packaged in ordinary paper bags or in plastic wrap.

A dry, but soft, pet food is produced in U.S. Pat. No. 4,039,689 usinglow temperatures and pressures. The use of the low processingtemperatures, less than about 130° F., leads to the soft dry nature ofthe pet food, it is disclosed. Meat and meat by-products as well asdried animal by-products can be used as a protein source for the petfood in U.S. Pat. No. 4,039,689. The dried animal by-products includemeat and bone meal.

U.S. Pat. No. 4,055,681, like U.S. Pat. No. 4,039,689, produces a softdry pet food having a meat-like texture and appearance. Meat meal isdisclosed as a protein source and fresh meat and meat by-products areused to impart palatability to the pet food.

In the production of the dry pet food products according to theprocesses of the above patents, the use of wet meat products causesubstantial smearing or blending of the meat into the farinaceousmaterial. It also causes bleeding of the protein colors into thefarinaceous material which reduces the visual attractiveness of theproduct to the consumer and which reduces the product's hardness.

A hard dry pet food is produced in U.S. Pat. No. 4,145,447. Highpressures of at least about 100 p.s.i. are used to obtain a productwhich is hard enough to provide chew-resistance for the removal ofplaque or tartar from the animal's teeth. The product is a long-lastingone which requires about 30 minutes to 2 hours for a 25 lb. dog toconsume. Dry components are mixed until homogeneous and then sufficientwater is added to wet the product without affecting the apparent dry,free-flowing characteristic of the product. The wetted product is thencompacted, at a pressure of at least 100 p.s.i., followed by heating orbaking the compacted product at a temperature of at least 200° F. Theproduct can contain air-dried, freeze-dried or irradiated foods such asmeat, fish, fish meal, cereals, fruits, vegetables and the like. Proteinfibers, such as those derived from soy protein and wheat gluten, oranimal fibers, such as those derive fro skin, muscles, and intestines,are optionally added to support the structure of the product. The animalfibers can be prepared by cutting, chipping, grinding, shredding,shearing or beating animal skins such as cowhide or rawhide. The highpressures used in the process of U.S. Pat. No. 4,145,447 make theprocess costly. Also, the structure-supporting fibers derived fromanimal tissue, which are optionally used in the process of U.S. Pat. No.4,145,447, are low in palatability. Furthermore, a product havingdiscrete, visually apparent, meat particles is not disclosed.

U.S. Pat. Nos. 4,125,149 and 4,229,485 disclose processes for improvingthe palatability of dry pet foods by applying a coating which containsproteins derived from animals, to the surface of the pet food. In U.S.Pat. No. 4,215,149 the surface of the pet food is treated with fat andthen with a phosphoric acid salt. Treatment of the surface of the petfood with meat flavors and animal proteins is optional. Heating of thecoated pet food, it is disclosed, must be avoided.

In U.S. Pat. No. 4,229,485 a dry biscuit is coated with a continuousglazed liver coating and is then baked to less than 18 percent moistureby weight. The liver preferably constitutes at least about 50 percent byweight of the coating, exclusive of moisture. The liver coating containsfarinaceous material and comminuted liver. The hard glazed coating, itis disclosed, has the visual appearance of a meat coating to enhance theproduct's attractiveness to pets. The dry biscuits to which the livercoating is applied are obtained by baking a combination of uncookedfarinaceous material and uncooked meat or meat by-products. The use ofthe uncooked meat or meat-products in the form of finely cut flakes,preferably having their largest dimension in the range of 15/1000 inchto 250/1000 inch, it is disclosed, is necessary for obtaining highpalatability of the product. However, the use of uncooked meat or meatby-products results in the blending of the protein color into thefarinaceous material. Additionally, the flakes present in the biscuitare not visually apparent because of the liver coating.

U.S. Pat. No. 4,310,558 teaches producing a dry pet food productcontaining fibrous food pieces having a tough, pliable texture combinedwith a basal matrix containing proteinaceous and farinaceous materialshaving a porous texture and appearance. The fibrous food pieces, whichmay simulate vegetables, grains and red meat pieces, comprise denaturedproteinaceous material. The food pieces are blended with undernaturedproteinaceous materials and farinaceous materials. The mixture ismechanically worked under conditions of elevated temperature andpressure and finally extruded to form an expanded dry pet food producthaving a porous texture interspersed with food pieces having a tough,pliable fibrous texture. The mechanical working and forming is basicallydone in a cooker extruder, which utilizes high shear annd substantialpressure.

BROAD DESCRIPTION OF THE INVENTION

An object of the invention is to provide dry hard canine biscuits havingdiscrete meat and/or meat by-products particles distributedsubstantially uniformly throughout the biscuits. Another object of theinvention is to provide a method for making such dry hard caninebiscuits. A further object of the invention is to provide dry hardcanine biscuits and method of producing such biscuits which overcomesthe disadvantages of the above prior art. Other objects and advantagesof the prior art are set out herein or obvious herefrom to oneordinarily skilled in the art.

The objects and advantages of the invention are achieved by the dry hardcanine biscuit and the production method of the invention.

According to the invention, there is provided a dry hard canine biscuithaving discrete, meat and/or meat by-product particles distributedsubstantially uniformly throughout the biscuit. The particles arevisually apparent as discrete particles, do not separate from theremaining, or farinaceous portion of the biscuit during shipping, andenhance the palatability of the biscuit by providing a flavor impact.The product is highly stable and can be packaged directly into a paperboard box. The method for making the dry hard canine biscuit of thepresent invention is economical, does not involve the use of highpressure and/or high shear to compact the biscuit dough as in U.S. Pat.Nos. 4,145,447 and 4,229,485, avoids substantial bleeding of the animalprotein color into the farinaceous material, maintains particlediscreteness and achieves substantially uniform distribution of theparticles throughout the biscuit. It is not necessary to use a foodgrade dye in the particles.

The invention includes a method for making a dry hard canine biscuithaving enhanced palatability and enhanced eye appeal. Discrete meatand/or meat by-products particles are distributed substantiallyuniformly throughout the dry biscuit and are visually apparent to theconsumer as discrete particles. The presence of meat and/or meatby-products particles substantially above or on the biscuit surface iskept to a minimum to reduce the opportunity for meat particle loss fromphysical abuse during transit. This particle distribution isaccomplished by first dry-blending the meat and/or by-products particleswith the non-fat solids portion of a biscuit dough, admixing thedry-blended mixture with water and then adding the fat portion of thebiscuit dough to form a dough. The invention process forms the doughusing low pressure and/or low-shear (preferably as little pressureand/or shear as possible) forming means or techniques. Alternatively,the water and fat can be admixed simultaneously with the dry-blendedmixture. Visual awareness and biscuit hardness maintenance of the meatand/or meat by-products particles is achieved by using particles whichare inert with respect to the biscuit dough. Inertness of the meatand/or meat by-products particles is made possible through the use ofparticles: (a) having a moisture content of 35 percent by weight orless; and (b) having a water activity which is less than the wateractivity of the biscuit dough during mixing, if the biscuit doughingredients were mixed without the meat and/or by-products particles.

DETAILED DESCRIPTION OF THE INVENTION

The dry, hard canine biscuit of the invention comprises discrete,visually apparent meat and/or meat by-product particles which areuniformly distributed throughout the biscuit. The remaining, or non-meatand/or non-meat by-product particle portion of the biscuit issubstantially free of meat particle color. The biscuits are very stablemicrobiologically, and can be stored without refrigeration and without apackaging barrier material such as plastic film. The biscuit can be invarious shapes such as square, round, triangular, animal-shaped and thelike. The preferred shapes are round, T-bone shape and a chop orsteak-like shape. The biscuits can have a thickness typical of caninebiscuits. A preferred thickness is about 1/2 inch.

The meat and/or meat by-product particles used in the invention can bein the form of specs, flakes, chunks, chips, granules and the like. Theparticles should be of sufficient size so as to be visually apparent tothe consumer as discrete particles when in the biscuit of the invention.Prior to incorporation into the biscuit, the meat and/or by-productparticles should preferably have a diameter of granulation of betweenabout 1/32 of an inch and 1/2 of an inch. The final biscuit will haveparticles approximately in this size range too. Mixtures of particleswithin this size range or particles having a given size within thisrange can be used.

Particle visual awareness and biscuit hardness maintenance are achievedby using meat and/or meat by-products particles which are inert withrespect to the biscuit. By meat and/or meat by-product particle"inertness" is meant: (a) that the particle does not smear into thebiscuit dough and retains its integrity through production of the finalproduct: (b) that the meat and/or meat by-product particle color doesnot substantially bleed into the biscuit dough; and (c) that ingredientswithin the meat and/or meat by-product particles do not adversely affectthe hardness and microbiological stability of the final biscuit product.

Meat and/or meat by-product particle inertness is made possible by usingmeat and/or meat by-product particles having: (1) a moisture content ofabout 35 percent by weight or less; and (2) a water activity which isless than the water activity of the biscuit dough during mixing of thedough, if the biscuit dough ingredients were mixed without the meat ormeat by-product particles. The lower water activity of the meat and/ormeat by-product particles substantially prevents the flow of water andprotein color from the particles to the dough during mixing of the doughingredients and the particles. Higher moisture content and wateractivity above that of the dough would cause smearing of the softerparticles into the dough, thereby losing meat and/or meat by-productparticle integrity. Also, higher moisture contents could create hardnessreduction by the formation of steam pockets which turn into air voidsupon biscuit leavening. The discreteness of the particles is locked induring drying of the dough.

Fresh meat and/or meat by-products can be dehydrated by known methods toachieve a moisture content of less than about 35 percent by weight.Dehydration also reduces the water activity of the meat and/or meatby-products. Generally, fresh beef has a moisture content of about 65percent by weight and a water activity of about 1.0. Dehydrating thefresh meat to a moisture content of about 40 percent results in a wateractivity of about 0.8. Dehydration to about 12 to 20 percent by weightof water results in a water activity for the meat of about 0.7 andlower. Biscuit doughs generally have a water activity of about 0.90 andabove upon completion of mixing of the non-fat solids portion, the waterand the fat portion of the dough. Preferably meat and/or meatby-products having a moisture content of less than or equal to about 20percent by weight are used because they remain shelf stable withoutrefrigeration prior to incorporation into the biscuit.

Microbiological stability of the meat and/or meat by product particleingredient is preferably achieved through a low water activity of 0.70or less. This low water activity is preferably achieved by dehydration.However, the water activity can also be lowered by other processes knownin the art. For example, to reduce the water activity, food additivesconventionally used for this purpose such as glycerin, propylene glycol,salt, corn syrup, sugar and the like can be included in the meat and/ormeat by-product particles in conventional amounts.

Commercially available meats and/or meat by-products having the abovelow water activity can be used for the meat and/or meat by-productparticle ingredient of the invention. Microbiological stability of themeat and/or meat by-products can be also be achieved even at wateractivities above 0.70 by the use of antimycotics and/or antibioticsconventionally used in the art for this purpose. Exemplary of theantimycotics which can used are potassium sorbate, sorbic acid, sodiumbenzoate and the like. Suitable commercially available meat productsand/or meat by-products which can be used are those which are storedwithout refrigeration and are packaged in a film of no more than 5 g persq. cm per 24 hours water vapor transfer rate. The meat and/or meatby-product particles should also be in compliance with NRC nutritionalrequirements such as 40 percent minimum protein content.

The substantial absence of meat and/or meat by-product particle colorbleed into the biscuit is principally due to the use of meat productswherein the color is formed as part of the protein matrix. In these meatproducts the protein is present in its least soluble form, namelydenatured and coagulated, and therefore the color is also insoluble.Accordingly, bleeding of the meat protein color into the remainingportion of the biscuit cannot take place.

Visual awareness of the meat particles is also effected by using meatproducts having a dark brown denatured meat protein color. Productshaving a denatured meat protein color as measured by an Agtronreflectance value of 10 or less contrasts excellently with typicalbiscuit doughs to effect visual awareness.

The term "meat" is understood to apply not only to the flesh of cattle,swine, sheep, goats, horses and whales, but also to other sources ofanimal protein, such as poultry and fish. Th term "meat by-product"refers to those non-rendered parts of the carcasses of slaughteredanimals, including but not restricted to mammals, poultry and fish, andincludes constituents such as liver, kidney, heart, spleen, tongue,trimmings, lungs and skins, embraced by the term "meat by-products" inthe Official Publication, "Official and Tentative Definitions of FeedIngredients," published by the Association of American Feed ControlOfficials, Inc., (1979), p. 94. The flesh of some animals, such as fishand poultry may be too light in color to provide sufficient contrastwith the biscuit dough so as to enhance visual awareness of the meatparticles. In this case, known food colorings can be added to the meatto enhance visual awareness. The meat particles and the meat by-productparticles can be used alone or in combination. Each particle can containboth meat and meat by-products from one or more animals.

The preferred meat and/or by-product particles are particles ofdehyrated cured meat, most preferably from ground beef. Spiced,dehydrated cured meat particles are highly palatable, have an appetizingodor and are particularly preferred for use in the canine biscuits ofinvention. The preparation of dehydrated cured meat, spiced or unspiced,is well-known in the art and does not form a part of the invention.Suitable dehydrated cured meat is commercially available and is commonlyreferred to as jerky, jerked beef or jerked meat.

Commercially available, dehydrated cured meat products which containmore than 35 percent moisture can be dried in a conventional manner towithin the above moisture content range.

Known biscuit dough formulations for the preparation of dry hard caninebiscuits can be used in the production of the biscuits of the invention.As indicated above, these doughs generally have a water activity ofabout 0.90 and above upon completion of mixing of the dough ingredients.A suitable dough contains farinaceous material, an edible oil, anantioxidant, an antimycotic, salt, animal fat, and added vitamins andminerals, such as those disclosed in U.S. Pat. No. 4,229,485 at column5, lines 7 to 57. The compositions of the invention also preferablycontain at least one animal-derived proteinaceous meal such as meatmeal, bone meal and fish meal. A preferred biscuit dough for producingthe biscuits of the invention contains about 50 to 60 percent by weightof wheat flour, about 5 to about 10 percent by weight of soybean mean,about 3 to about 10 percent by weight of meat and bone meal, about 1 toabout 5 percent by weight of wheat meal, about 1 to about 5 percent byweight of animal fat preserved with BHA, about 20 to about 30 percent byweight of water, and about 2 to about 5 percent by weight of naturalflavors, vitamin and mineral preblend, and acidulant. More generally,useful biscuit doughs can contain about 15 to about 35 percent by weightof water and about 0.5 to about 10 percent by weight of fat.

The relative amount of the meat and/or meat by-product particles and thebiscuit dough should be such so as to result in a dried biscuit productwherein the weight percent of the particles is about 3 to about 15percent by weight, preferably about 5 to 10 percent by weight, of thefinal dried biscuit product. Compliance to NRC nutritional requirementsis enhanced by even these low levels of the 40 percent minimum proteinmeat and/or meat by-product particle. Lower or higher levels of the meatparticles can be used provided biscuit integrity is maintained, the meatparticles do not extend appreciably above the surface of the biscuit soas to separate from the biscuit during shipment, the final productremains visually attractive to the consumer, and the product iseconomical to produce.

In producing the dry, hard canine biscuit of the invention the meatand/or meat by-product particles are blended with the solid non-fatportion of the biscuit dough. By incorporating the meat particles intothe solid non-fat portion of the biscuit dough, the meat particles aredistributed substantially uniformly throughout the final biscuitproduct. The portion of the particles at the surface of the biscuit arevisually apparent as discrete particles. Particles substantially belowthe surface however are also of sufficient size and integrity to bevisually apparent as discrete particles upon breaking the biscuit intwo, for example.

All mixing can be done at 20 to 100 rpm. The dry-blending step istypically conducted at room temperature for a period of time of about 3minutes to about 10 minutes so as to obtain a uniform mixture of themeat and/or meat by-product particles and non-fat portion of the biscuitdough. The dry-blended mixture is then mixed with the hot water to forma first stage dough. This methodology minimizes the occurrence of meatand/or meat by-product particles substantially above and on the finalbiscuit surface. As a result, the opportunity for meat and/or meatby-product particle loss from physical abuse during transit is reduced.The water which is admixed with the dry-blended mixture is typically ata temperature of about 65° to about 150° F. The hot water is added, withmixing, over a period of time of about 3 minutes to about 5 minutes toform the first stage dough. Then the fat portion of the biscuit dough isadmixed with the first stage dough to form the final stage dough. Thefat portion is added at a temperature at which it is at least fluid,typically at about 100° to about 150° F. The fat portion is mixed for aperiod of time which is sufficient to form a dough whose homogeneity isvisually apparent. A typical final mixing time is about 3 minutes toabout 5 minutes.

Formation of the dough is achieved at about atmospheric pressure withmixing of the components being conveniently achieved in an upright sigmablade mixer or other bakery-type mixers. The various ingredients can beadded over a period of time or in a one-shot manner according to theabove order of addition. However, melted fat and water may be addedsimultaneously and mixed 6 to 10 minutes.

The dough is then formed into pieces by machining on a rotary molderwith specific die shapes. The dough can also be formed into pieces bysheeting followed by either a vertical or rotary cutter or by a rotarymolder. Hardness of the final biscuit is enhanced by sheeting the doughprior to cutting or molding. Suitable die and cutter shapes are thosewhich result in a round, square, triangular, T-bone or chop shapedbiscuit product and the like. The forming is accomplished atconventional temperatures of ambient to 110° F. and pressures of lessthan 75 p.s.i. (gauge), used with for example a rotary molder, avertical cutter of rotary cutter. An essential or critical feature ofthe invention is that the forming of the dough piece is done using lowshear and/or low pressure forming means or techniques. High shear orhigh pressure forming will decimate or smear the meat and/or meatby-products particles and/or will cause bleeding or running of any dyeused in the particles. The forming pressure is less than 75 p.s.i.g.

The formed pieces are then baked, followed by drying, to achieve a shelfstable product without the need of a moisture barrier protection. Bakingand drying temperatures and times are those conventionally used in theproduction of a hard, dry canine biscuit. The pieces are dried to obtaina biscuit having a water activity of 0.70 or less. Typical bakingtemperatures and times are about 300° F. to about 475° F. for about 25minutes to about 8 minutes. Drying conditions are typically about 200°to about 325° F. for about 25 minutes to about 12 minutes in a forcedair dryer. On a weight basis, the moisture content of the final biscuitproduct is less than or equal to about 15 percent by weight andpreferably about 10 to about 12 percent by weight of the final biscuitat 70 percent relative humidity.

While typically adding meat to a biscuit softens it, the final driedbiscuits of the invention should be sufficiently hard to stimulate thejaw bones and clean the teeth of canines. The hardness of the finalbiscuit of the invention as measured in a cracking test on a Dillondynamometer should be about 30 to about 50 lbs. for a 1/2 inch thicksample using a pinpoint tester having a 3/32 inch diameter tip. The tiphas a concave bottom with a maximum depth of 1/16 inch. In this test,the hardness reading in pounds is linearly proportional to the samplethickness. Thus, a 1/4 inch thick sample should have a hardness of about15 to about 25 lbs. An essential or critical feature of the invention isthat the forming of the hard dough pieces is done using low shear and/orlow pressure forming or techniques. High shear or high pressure formingwill decimate or smear the meat and/or meat by-product particles and/orwill cause bleeding or running of any dye used in the particles. Theforming pressure is less than 75 p.s.i.g.

Non-cooking forming conditions herein means that the forming is achievedat a temperature whereby none of the protein in the hard dough materialis denatured and none of the starch in the hard dough material isgelatinized. Low-shear forming conditions herein means that forming isachieved at 25 sec.⁻¹ or less. (High shear herein means greater than 25sec.⁻¹, which excludes the use of high-shear cooler extruders in theinvention.) See Rossen & Miller, "Food Extrusion", Food Technology, Aug.1973, pages 46 to 53, (especially page 52).

The invention is further illustrated in the following examples whereinall percentages, parts, ratios and proportions are by weight and alltemperatures are in °F., unless otherwise stated herein or otherwiseobvious herefrom to one ordinarily skilled in the art.

EXAMPLE 1

In this example, spiced dehydrated cured beef granules having a moisturecontent less than 35 percent by weight, a granulation between 1/32 of aninch and 1/2 inch, and having a dark brown denatured meat protein colorof Agtron reflectance value of 10 or less were used. The spiceddehydrated cured meat granules were obtained by granulating dehydratedcured meat having the composition:

    ______________________________________                                        Dehydrated Cured Meat Pounds                                                  ______________________________________                                        Meat By-Products      650                                                     Meat                  268                                                     Natural Flavors       1                                                       Spices                29                                                      Cure (Sodium Nitrate) 1                                                       Potassium Sorbate     0.5                                                                           949.5  pounds                                           ______________________________________                                    

Then, 75 pounds of the spiced dehydrated cured meat granules werecombined with the non-fat solids portion of a biscuit dough, the fatportion of the biscuit dough and water to form a dough in accordancewith the process of the invention. The ingredients, relative amounts,and the process for making the biscuits were:

    ______________________________________                                        Biscuit and Meat Chips Pounds                                                 ______________________________________                                        Wheat Flour            940                                                    Soybean Meal           135                                                    Dehydrated Cured Meat  103                                                    Meat and Bone Meal     100                                                    Wheat Meal             40                                                     Animal Fat preserved with BHA                                                                        32                                                     Natural Flavors        17                                                     Vitamin and Mineral Preblend                                                                         25                                                     Acidulant              4                                                      Water                  490                                                                           1886   pounds                                          ______________________________________                                    

The dehydrated cured meat was dry-blended with the solid non-fat portionof the biscuit dough in an upright sigma blade mixer at 20 rpm for 10minutes. Then, the 490 pounds of water at a temperature of 150° F. wasadded together with 140° F. fat to the preblend and mixed for 6 minutesto form the dough. The dough was then machined on a rotary molder havinga die engraved to a depth of 0.415 inch for the formation ofapproximately 1/2 inch thick round, T-bone and chop shapes. The formedplaces were then baked in a band oven for 9 minutes followed by dryingat 250° F. for 20 minutes in a band dryer to achieve a dry, hard shelfstable product. The baking temperatures in the band oven were:

    ______________________________________                                        Band Oven Baking Temperatures                                                                       Zone                                                    ______________________________________                                           530° F.     1                                                       530                   2                                                       550                   3                                                       540                   4                                                       400                   5                                                       520                   6                                                       Off                   7                                                       Off                   8                                                       Off                   9                                                       ______________________________________                                    

The product was dump-packed into a carton without the need for moisturebarrier protection.

Hardness tests on the product using a Dillon dynamometer as describedabove resulted in hardness readings in the range of 30 to 50 lbs.

The product and biscuits prepared in the same manner except for theinclusion of the meat granules were fed to dogs in 35 tests. The numberof dogs in each test ranged from 11 to 32. The feedings were for 3consecutive days in a split plate for testing preference. The biscuitswere fed as a treat 4 to 5 hours after each dog's main meal. The mainmeal supplied 100 percent of each dog's calorie demand. The biscuitcontaining the meat granules were preferred up to 8:1 indicating astatistically significant preference level.

EXAMPLE 2

A Cruesot Loire BC72 cooker extruder, having 1000 mm barrel, two barrelheaters and cooling means, was used. A base formulae or mixture wasmixed in a dry ribbon blender and then passed to the cooker extruder.

The base formula, on a per batch basis, are:

    ______________________________________                                        Ingredients        Amount                                                     ______________________________________                                        Wheat flour        58 lbs. 12     oz.                                         Soyabean meal      8 lbs.  7      oz.                                         Natural flavors            5      oz.                                         Wheat meal         2 lbs.  8      oz.                                         Meat and bone meal 6 lbs.  4      oz.                                         Salt                       10     oz.                                         Vitamin-mineral premix     12     oz.                                         Natural flavors            12     oz.                                         Acidulant                  103    grams                                       Tallow             1 lb..sup.                                                 Total              76 lbs. 2      oz.                                         ______________________________________                                    

All of the ingredients except the tallow were screened through a U.S.No. 10 Mesh screen. Beef jerky was used which went through a U.S. No. 4Mesh screen and stayed on a U.S. No. 8 Mesh screen. All of the dry blend(base formula) was dry blended in the ribbon blender for 10 minutes.Depending on the particular experiment, various amounts of beef jerkyparticles were added to the mixture and the mixture was dry blended in aHobart mixer. The tallow was then added to the subsequent mixture,followed by further dry blending to achieve a uniform mass.

The specifics are as follows:

    ______________________________________                                                                          Amount of                                   Experiment            Water Content                                                                             Oil Sprayed                                 No.     Amount of Jerky                                                                             of Jerky    in Jerky                                    ______________________________________                                        H-1E    None          --          --                                          H-2E    4 lbs. 2 ozs./                                                                              12%         1%                                                  76 lbs. 2 ozs.                                                                of base formula                                                       H-3E    4 lbs. 2 ozs./                                                                              25%         1%                                                  76 lbs. 2 ozs.                                                                of base formula                                                       H-4E    4 lbs. 2 ozs./                                                                              35%         1%                                                  76 lbs. 2 ozs.                                                                of base formula                                                       H-2RM+B 17 lbs/1202 lbs.                                                                            12%         None                                                of base formula                                                       H-5E+B  34 gm/273 gm. of                                                                            12%         None                                                base formula                                                          ______________________________________                                         Notes:                                                                        (a) H means base formula according to the abovecited ingredient               proportions.                                                                  (b) RM+B means rotary molder followed by baking in a band oven                (c) B means baking in a reel oven.                                            (d) E means extrusion.                                                        (e) The oil was sprayed on the jerky granules to simulate the preferred       teaching in the U.S. Pat. No. 4,310,558 (Nahm), but the oil did not           prevent the jerky granules from being decimated by the highshear extrusio     or from being torn apart upon exiti ng from the extruder dye as the dough     product expanded.                                                        

The control (H-1E) and the three experiments representing Nahm (H-2E toH-4E) were subjected to high shear cooker extrusion after dry blending.The data on the extrusion is:

    ______________________________________                                                           Extruder          Percent                                  Material                                                                             Extruder    Screw     Extrudate                                                                             Added H.sub.2 O                          Extruded                                                                             Pressure Die                                                                              Speed     Temp.   in Extruder                              ______________________________________                                        H-1E   103 to 146 psig                                                                           160 r.p.m.                                                                              160° F.                                                                        10                                       H-2E   150 psig    115 r.p.m.                                                                              166° F.                                                                        15                                       H-3E   122 to 182 psig                                                                           110 r.p.m.                                                                              172° F.                                                                        15                                       H-4E   160 to 186 psig                                                                           190 r.p.m.                                                                              176° F.                                                                        15                                       ______________________________________                                         Note: The extrudate temperatures were all over 160° F., which is a     least sufficient to denature the protein. The material in the extruder wa     at a higher temperature because there was a flash off of the water as it      exited from the extruder.                                                

Further data on the extrusions is:

    ______________________________________                                        Material                                                                              Extruder Barrel                                                                            Extruder     Extruder Die                                Extruded                                                                              Heaters      H.sub.2 O Coolant                                                                          Opening                                     ______________________________________                                        H-1E    183°, 132° F.                                                                131° F.                                                                             3/8" × 3/16"                          H-2E    181°, 116° F.                                                                130° F.                                                                             3/8" × 3/16"                          H-3E    182°, 100° F.                                                                130° F.                                                                             3/8" × 3/16"                          H-4E    158°, 123° F.                                                                115° F.                                                                             3/8" × 3/16"                          ______________________________________                                    

More data on the extrusion and drying is:

    ______________________________________                                                                       Drying The                                     Material                                                                              Cutter      Extruder   Extrudate                                      Extruded                                                                              Blade Setting                                                                             Drive Load Temp.  Time                                    ______________________________________                                        H-1E    6           33 amps    200°F.                                                                        1.5 hr                                  H-2E    6           51 amps    200°F.                                                                        1.5 hr                                  H-3E    6           48 amps    200°F.                                                                        1.5 hr                                  H-4E    6           53 amps    200°F.                                                                        1.5 hr                                  ______________________________________                                         Note: The extrudates were dried in a Proctor Schwartz drier.             

In addition to the above runs, experiment H-1E-1 was conducted the sameas experiment H-1E except that the extruder pressure at the die was 250p.s.i.g., and experiment H-2E-1 was conducted the same as experimentH-2E except that the extruder pressure at the die was 247 p.s.i.g.

The invention was represented by experiments H-2E+B and H-5E+B. In eachcase the water content is the dough was 32 percent. Extrusion was donein a low shear extruder (i.e., a meat grinder, "Kitchen Aid Grinder",with blades) using a die opening of 0.5 inch diameter. The manual cutoff was 1 to 1.5 inch. The temperature of the extrudate was 90° F. andthe actual pressure at the exit point at the back of the die was 30 to40 p.s.i.g. The temperature of the dough processed in the low shearextruder never exceeded 105° F. and accordingly was not cooked in thelow shear extruder. Both extruded materials were then baked in a reeloven at 350° F. for 36 minutes.

The invention was further represented by experiment H-2RM+B. The watercontent of the dough was 26 percent. The dough was compacted in a rotarymolder at room temperature and at a pressure of less than 75 p.s.i.g.The compacted dough pieces were then baked in a band oven for 8 minutesusing a starting temperature of 600° F., which fell to 200° F., and weredried for 20 minutes at 275° F.

The pet food pieces prepared by the several experiments had thefollowing characteristics:

    ______________________________________                                                                     Agtron Color                                                                  (lower reading                                   Experiment                   means a darker                                   Number  Sensory Observations color)                                           ______________________________________                                        H-1E    Light tan; rough surface.                                                                          45                                                       Slight porosity noted on                                                      surface regions; random,                                                      very small particles                                                          visible.                                                              H-2E    Darker tan; rougher  43                                                       surface with many back-                                                       wards extending ridges                                                        over valleys. Porosity                                                        noted on surface regions.                                                     granules showing; a few                                                       random possibly smeared,                                                      very small particles.                                                 H-1E-1  Light tan; rough surface.                                                     Slight porosity noted on                                                      surface regions; random,                                                      very small particles                                                          visible.                                                              H-2E-1  Darker tan; rougher sur-                                                      face with any backwards                                                       extending ridges over                                                         valleys. Porosity noted                                                       on surface regions.                                                           Essentially no jerky                                                          granules showing; a few                                                       random, possibly smered,                                                      very small particles                                                          visible on the surface.                                               H-3E    Darker tan; rough surface                                                                          40                                                       with many backwards extend-                                                   ing ridges over valleys.                                                      Porosity noted on surface                                                     regions. Essentially no                                                       jerky granules showing; a                                                     few random, possibly                                                          smeared, very small                                                           particles.                                                            H-4E    Darker tan; extremely                                                                              38                                                       rough surface with any                                                        backwards extending                                                           ridges over valleys;                                                          poor definition. Poro-                                                        sity noted on surface                                                         regions. Essentially                                                          no jerky granules                                                             showing; a few random,                                                        possibly smeared, very                                                        small particles.                                                      H-2E+B  Light, golden, brownish                                                       tan; discrete, non-                                                           smeared, large jerky                                                          particle visible through-                                                     out; there was good jerky                                                     granule integrity through-                                                    out. Somewhat rough surface                                                   with some backwards extending                                                 ridges. No visible porosity.                                          H-5E+B  Light, golden, brownish                                                       tan; discrete, non-                                                           smeared, large jerky                                                          particle visible through-                                                     out; there was good jerky                                                     granule integrity through-                                                    out. Somewhat rough surface                                                   with some backwards extending                                                 ridges. No visible porosity.                                          H-2RM+B Light, golden, tannish brown;                                                 discrete, well defined, non-                                                  smeared, large jerky granules,                                                there was excellent jerky                                                     granule integrity throughout.                                                 Undulating, slightly pocked                                                   surface. Good color contrast                                                  between discrete jerk granules                                                and remaining biscuit surface.                                        ______________________________________                                    

What is claimed is:
 1. Dry hard canine biscuit consisting essentially ofdiscrete, visually-apparent, dehydrated particles, which contain meatand/or meat by-product, distributed substantially uniformly throughoutsaid biscuit, the remaining portion of said biscuit being substantiallyfree of meat particle color containing a major portion of at least onefarinaceous material, said biscuit having a water activity of 0.70 orless, and a water content of 15 weight percent or less, based upon thetotal weight of said dry hard canine biscuit, said particles beingpresent in an amount of about 3 to about 25 weight percent, based on thetotal weight of said dry hard canine biscuit, said particles having awater activity which is equal to or less than the remaining portions ofsaid biscuit, and said particles being non-expanded, of sufficient sizeto be discrete and visually apparent, substantially of a size whichpasses through a U.S. No. 4 Mesh screen and stays on a U.S. No. 8 Meshscreen, and having a water content of 12 to 20 weight percent, based onthe total weight of said dehydrated particles.
 2. The dry hard caninebiscuit as claimed in claim 1 wherein said remaining portion of saidbiscuit is non-expanded.
 3. The hard dry canine biscuit as claimed inclaim 1 wherein the farinaceous material is a glutenous farinaceousmaterial and wherein said remaining portion of said biscuit contains atleast one animal-derived proteinaceous meal.
 4. Dry hard canine biscuitconsisting essentially of discrete, visually-apparent, dehydratedparticles, which contain meat and/or meat by-product, distributedsubstantially uniformly throughout said dry hard canine biscuit, theremaining portion of said dry hard canine biscuit being substantiallyfree of meat particle color and containing a major portion of at leastone farinaceous material, said dry hard canine biscuit having a wateractivity of 0.70 or less, and a water content of 15 weight percent orless, based upon the total weight of said dry hard canine biscuit, saidparticles being present in an amount of about 3 to about 25 weightpercent, based on the total weight of said dry hard canine biscuit, saidparticles having a water activity which is equal to or less than theremaining portions of said biscuit, said hard dry canine biscuit beingshelf stable, said hard dry canine biscuit having said particles presentas discrete visually-apparent particles distributed substantiallyuniformly throughout, some of said particles being visible on thesurface of said dry hard canine biscuit, and said particles beingnon-expanded, of sufficient size to be discrete and visually apparent,substantially of a size which passes through a U.S. No. 4 Mesh screenand stays on a U.S. No. 14 Mesh screen, and having a water content of 12to 20 weight percent, based on the total weight of said dehydratedparticles.
 5. The dry hard canine biscuit as claimed in claim 4 whereinsaid remaining portion of said biscuit is non-expanded.
 6. The hard drycanine biscuit as claimed in claim 4 wherein said particles are cohesiveand have particle integrity.
 7. The dry hard canine biscuit as claimedin claim 4 wherein said dry hard canine biscuit has a hardnessequivalent to a reading of 30 to 50 lbs. for a biscuit having athickness of about 1/2 inch measured on a Dillon dynamometer having apinpoint tester with a 3/32 inch diameter tip having a concave bottom.8. The dry hard canine biscuit as claimed in claim 4 wherein saidparticles have a dark brown denatured meat protein color of Agtronreflectance value of 10 or less.
 9. The dry hard canine biscuit asclaimed in claim 4 wherein said particles contain a food coloring andwherein the remaining portions of said biscuit are substantially free ofsaid food coloring.
 10. The hard dry canine biscuit as claimed in claim4 wherein the farinaceous material is a glutenous farinaceous materialand wherein said remaining portion of said biscuit contains at least onanimal-derived proteinaceous meal.